Heating system



Fx. H. CORNELIUS ET Al. 2,169,601

HEATING SYS TEM Aug. 15, 1939.

Original Filed Oct. 4, 1934 K Y INVENTORS'. v '/06 5am( H. Corne//Z/s H3Wa /Mer /IK @ree/z,

Patented Aug. 15, 1939 UNITED STATES HEATING SYSTEM Frank H. Corneliusand Walker N. Green,

Wilkinsburg, Pa. v

Application october 4, 1934, serial No. 746,860 Renewed January 11, 193912 Claims.

Our invention relates to heating systems and it has particular relationto specialized apparatus for thisv purpose.

One object of our invention is to provide an improved method of andapparatus for heat exchange through a surface between uid media.

Another object of our invention is to provide a method of transferringenergy from one stream of fluid medium to another which comprises thesteps of transferring heat therebetween through an interveningconducting wall and adding an increment of mechanical energy to at leastone of said streams during the flow thereof on opposite sides of saidwall.

A further object of our invention is to provide in a heat exchanger aninherent characteristic of producing a usable increment of mechanicalenergy as a by-product of the heat exchange proper. y

Another object of our invention is to provide a heat exchanger wherein ahigh relative velocity of heat transferring media with respect to aheat-transferring surface is obtained in large part by means of movingsaid heat-transferring 5 surface.

A further object of our invention is to provide a heat exchanger inwhich the velocity of flow of one or both fluids through said exchangeris a relatively small component of the total relative velocity of theiuids with respect to the heattransferring surface.

Another object of our invention is to provide a heat exchanger of suchcharacter as to produce pressure that will cause one or both of themedia to flow through circulatory systems external to the exchanger.

A further object of our invention is to produce a surface heat exchangerhaving extremely small temperature gradients across the paths of theheat-transferring media.

Another object of our invention relates to a water or other liquidheating system in which the temperature difference between differentpoints in the liquid is utilized in producing mechanical energy, aportion of said mechanical energy being expended to produce circulationwithin the system.

Other objects of our invention will become evident from the followingdetailed description, taken in conjunction with the accompanyingdrawing, in which:

Figure 1 is a view, mainly in longitudinal section, of a heat exchangerconstructed inV accordance with the principles of our present invention;and f l Fig. 2 is a view, in transverse section, taken along the lineII-II of Fig. 1.

Referring to Fig. 1 of the drawing, the structure there shown comprisesa heat exchanger adapted for the transfer of heat between fluid media,having an outer shell or casing |0| which may be of frusto-conicalshape, with a suitable base or support |02, the lower part of saidcasing forming a toroidal space or envelope |03 and the upper partforming a laterally-projecting exhaust outlet |04. A rotating 4drum |05which may be of truste-conical shape, located within and spacedl fromcasing |0| so as to form an annular passage |06 leading from space |03to outlet |04, is supported at its upper and lower ends by hollow shafts|01 and |08, respectively, shaft |08 having a suitable bearing in base|02 and shaft |01 projecting through and having suitable bearings in anelectric motor or other driving means |09, or being otherwise suitablycoupled thereto. A second drum ||0 which may be of frusto-conical shapelocated within and spaced on all sides by a passage or space I from drum|05,rotates with drum |05 by reason of being attached thereto by meansof impeller blades ||2 at its top. Q5

A plurality of helical baffles ||3 located within the annular space |06are suitably aixedft'olcasii ing |0| and project radially toward drum'|05 terminating at a short distance therefromas Y.re quired for workingclearance. A stationary-holllow member 4 having curved "blades'iorguide'vanes H5, with passages ||6 therebet n," positioned in the space betweenthflower vendsA of rotating drums |05 and ,|"|0 is'"supportedfbyy ,Ystationary hollow shaf'tw'l |-|;'l vfwhic'liprojects through the hollowshaft? |08' nd'isfsecurred iii base 02 communicating with passa'geillthere" v and discharge pipe`f||0`therefrom f? One of the mostcommorifapplications fforisuch' a heat exchanger lies'i the-transfer `ofheat'fror the products of 'lc'ombus'tion'tol A ai liquid f mediufni Forsuch an application the toroidallspace |03 may serve asa-combustionlhamberfor'fgaseous fuel supplied .byla' pipe 1|20,:bui`v'r'1erlmanifoldfl 2 and burner 'tips' |22", fthe'- latterAprojecting @into space |03,- :Lair vfor 4combustion'ienteringthroughholes |23 through which@ -Ltheftipsuproject.1.Y `,'Such ap'plicationiis-notiflimitedfto the-usev lofl 'gaseous fuels, lbut'` canlob-viou'sladaptedto ftheffuse'of any',desir'edfuel.;`r -In e operation-theyIriovingi` drums l 051' and l1 |0 are rapidly rotated-:Eby motori-'109,IVcausingv the outer surfacefof fdrumf |0'5#tohavea'higlrrelativefvelocityrwithi respect-itc @thery :casingrz |f05| yand helical:bafiies, lil-3;v` l: '-'Products offcor-nbustion foi' vthe gases withinthe passages.

other heated media flow, as indicated by thedotted arrows, from theannular space |03 upward in annular space |06, which is divided into aplurality of helical passages bythe baffles I|3, the latter being sopitched that the products of combustion follow, in general, thedirectionof rotation of the drum. The friction between the products of combustionand the rapidly moving surface of Vdrum |05 tends to cause said productsof combustion to. rotate with the drum. By virtue of the small clearancebetween the baffles I3 and the 4drum |05 the only appreciable massrotation possible for the products of combustion is'that accomplished intraversing the helical passages. The friction between the moving'surface and the products of combustion thus exerts a positive forcedriving the latter in the desired direction. A further result of thisfriction is violenteddies in The availability of this positive drivingforce on the products of combustion permits the annular space |05 to bevery shallow which, in turn, reduces the temperature difference acrossthe gas passage.

After flowing through the passages |00 the gases pass out the dischargeport |04 which may be connected with a suitable discharge pipe or stack.Y

A second medium, such as a liquid, to which heat is being transferredthrough the wall of the drum |05 from a medium such as the products ofcombustion in Vthe passage |06, may be introduced' into the annularspace betweenthe drums |05 and I I0 by means of the hollow shaft |01,where it is acted upon by the impeller blades H2, receiving therefrom'arotary motion causing it to Vflow rapidly outward, as indicated by thesolidl arrows, from the axis to the periphery of the drums and throughthe annular space flowing thence into the space containing stationarymember ||4 where it is actedv upon by stationary blades ||5 causing itto flow back toward the axis of rotation, and out through hollowshaft |8and discharge pipe ||9 Yto the place of application.

Obviously, a medium such as liquid' could be caused to now through thedevice in the manner described by means of an external source ofhydrostatic pressure or by gravity without the use of impeller blades||2, Vstationary,member ||4 and blades-I I5; however, since manyapplications of such a heat-transferring apparatus cause it to beassociated with an external circulatory system through which the liquidmust be forced against the resistance thereof, itis desirable,

' propriate design of .said stationary member, Athe medium can b e madeto arrive at this point with any desired degree of rotationalvelocitylup to kthe full velocity ofthe drums( Since the liquid can thus bebrought to this point having any desired degree of kinetic energydue toits rotation, suitable means such as stationary member ||4 will convertan appropriate part of such kinetic energy into hydrostatic pressure ofthe v medium.

stationary member IM and at the same time approaching said peripherywill strike theextremity of blades H5 and be deflected into the passages|56 between said blades of the member ||4, the entrant velocity beingapproximately equal to the linear velocity of rotation just prior toentry. By suitable proportionment of the passages within member l it,the cntrant'velocity may be progressively decreased with the attendantconversion of the decrement of velocity energy into hydrostatic pressureas the iiuid traverses the member,v such pressure being available at thedischarge/outlet H9.

In order more clearly to explain the nature of the flow of the liquid upto its entry into the stationarymember H4, let it be assumed that theimpeller blades ||2 are omitted from the structure or in some mannermade inactive, also that the earths gravitational force is inactive withy respect tothe fluid. If then a lquantity of the v drum may beconsidered as having no rotational velocity and there will be on thataccount a high relative velocity of the rotating surfaces with respectto the mass of theliquid. Contact with the rotating surfaces will impartto the liquid in unit time a certain degree of rotation depending uponthe viscosity of the liquid and the proportions of the passage.

As soon as the liquid begins to rotate, the centrifugal force due tosuch rotation will cause it to move outwardly from the axis of rotation.This action will carry the liquid into zones of constantly increasingsurface linear velocity of rotation of the liquid is thus continuouslyaccelerated by virtue of the relative velocity existing between theliquid and moving surfaces, reaching a maximum at the periphery of thestationary member I4. However, so long as the liquid is moving away fromthe axis of rotation, its linear velocity of rotation cannot forces suchas gravity or hydrostatic pressure.

It has beenfound in the transfer of heat between gaseous and liquidmedia through a surface that the chief limitations lie upon the gaseousside rather than the liquid side of the surface. While the rate of heattransfer is improved by having a high relative velocity between theliquid and the surface, it is not necessary or desirable to have theextremely high order of relative velocity that s desirable between thesurface and the gas. We rlnd that the total relative velocityV betweenthe liquid and the surface which is the vectorial sum of the relativevelocity due to rotational slippage, and the relative velocity betweenthe liquid and the surface arising from the progress of the liquid in anaxial direction as it passes through the apparatus, is of a very highorder when theV apparatus is operating without impeller blades H2. Forthat reason it is advantageous to make use of .impeller blades ||2 whichincrease the rotational velocity o-f the liquid and reduce therotational slippage, thus delivering the liquid with a higher degree ofkinetic velocity.Y The energy to be converted into hydrostatic pressureby the stationary member H4.

At a given angular velocity the degree of rotational slippage at thesmaller or top radius of the drum H35 is governed by the design of theimpeller blades H2, and the rotational slippage of the fluid as itprogresses along the drums is governed by the width Aof the passage III,the rate of change of the drum diameter, the viscosity of the liquid andthe volume of liquid flowing through the apparatus in unit time. It isthen possible to produce any desired total relative velocity between theliquid and the surface, within very wide limits, by suitableproportionment of the first four of these controlling factors; viscosityof the liquid, of course is incapable `of arbitrary adjustment.

The friction between a surface and a fluid moving relative thereto isassociated in such a way with heat transfer that an increase infrictional resistance due to increased velocity will increase the rateof heat transfer, other things being equal. Thus, the power ormechanical energy that is consumed in overcoming frictional resistancebetween the heat-transferring surface and a fluid moving relativelythereto is useful in improving the rate of heat transfer. But the powerof energy consumed in imparting velocity energy to a fluid to cause itto flow along a stationary surface is of no value in improving heattransfer and is to that end wasted, or at best may be only partiallyrecovered by means of additional costly apparatus.

Further, the frictional resistance due to the high relative velocityexisting between surface and fluid is useful in our invention as a meansof adding an increment cf mechanical, that is pressure and/or velocity,energy to the fluid stream.

The desirability of heat transfer between streams of fluid moving incounterflow relation is well known in the art. The method and apparatuscomprising our invention effects such counterow heat exchange. vIt willbe noted that, while the actual motion of the one stream of fluid withrespect to the other stream of iiuid is rather in the nature ofcross-flow than counterow, still there is substantially no temperaturegradient in an angular direction about the axis of rotation in eitherstream, and the maximum of temperature gradient in either stream existsin a plane containing the axis of rotation and in a direction parallelto the heat transfer surface; this is the condition of counteriiow heatexchange.

A further desirable feature of our apparatus lies in the fact that it issuited to the use of fluid passages that are narrow or shallow in adirection normal t the heat exchange surface. By virtue of the fact thata fluid is transferring heat with a surface, there exists in the fluid atemperature gradient in a direction normal to the surface. Y Themagnitude of the gradient, in addition to depending on the thermalconductivity of the fiuid, also depends on factors which will bringremote parts ofthe fluid close to the surface. There is in our apparatusa considerable degree of agitation in the fluids due to high relativevelocities with respect to the surface which constantly. brings newportions of the fluids into contact with the surface. There is alsooperating a positive force which selectively acts to bring those partsof the fluid most differing in temperature from the surface into contactwith the surface; this force is centrifugal force. Considering that heatis being transferred from the outer to the inner medium, those parts ofthe inner medium most remote from the surface are cooler and more densethan those parts immediately next the surface; being more dense, thecooler parts are caused by centrifugal force to displa-ce the warm.- erparts at the surface. The reverse condition existing upon the side ofthe outer medium causes parts of the fluid cooled at the surface tomovel away from the surface to be replaced by warmer parts. All of thesefactors operate to make the said temperature gradient across the iiuidpassages a minimum. In view of this small temperature gradient, the factof narrow passages makes possible an extremely small total temperaturedifference across the passages. Such small temperature differencematerially reduces the overall temperature head required to secure agiven heat transfer, other factors being equal; or, stated in otherwords, it permits the use of a smaller heat exchange surface for a givenoverall temperature difference and a given heat load.

One notable feature of such a novel heat exchanger is that by virtue ofthe high frequency and short period of contact between any, fluidparticle and the surface, it can be used as adirect fired apparatus forheating liquids that are easily damaged by heat, as for example milk,`

fruit juices, or other liquids containing animal or vegetable matter. i

Another extensive field of application for the direct fired form ofapparatus with its means for producing positive liquid pressures, liesin its use as a heating boiler for hot water or similar systems ofheating buildings or the like where both the small physical size of theapparatus as compared with stationary equipment andthe assurance ofrapid and positive circulation of the liquid through piping systems areof especial value.

While the apparatus has been shown as a direct fired heat exchangerhaving means for positively moving the products of combustion and meansfor creating considerable hydrostatic pressure in a liquid which isbeing heated, it will be appreciated that this is only one of manypossible modifications of our system of heat exchange.

While we have shown and described one embodiment of our invention, we donot wish to be limited to the particular structural details thereof,since modifications may be made without departing from the spirit andscope of our invention. We desire, therefore, that only such limitationsshall be imposed thereon as are indicated in the appended claims.

We claim as our invention:

1. In a heat exchanger for the transfer of heat, a wall of heatconducting material in the form o-f a surface of revolution adapted tobe disposed between streams of fluid mediums, a static-nary wall spacedfrom said surface, a plurality of baffles secured to the stationary walland extending to a point adjacent said surface, said baffles beingcurved at an angle to the axis of rotation of said surface of revolutionand in the general direction of rotation thereof whereby the rotation ofsaid surface cooperates with said baffles to produce a high relativevelocity in a stream of fluid positioned between the stationary wall andsaid surface. v

2. In a heat exchanger for the transfer of heat,

a Wall of heat conducting material in the form 'z5 of a surface ofrevolution adaptedto be disposed between streams of fluid mediums meansinclude ing stationary baiile'means for effecting relative rotation ofsaid wall and oneof said streams to secure a high relative velocity ofsaid last-named Y stream with respect to said wall, a second wall spacedfrom said first named wall, said baiile means being supported from saidseco-nd wall and being curved at an angle to the axis of rotation. ofsaid surface of revolution and in the general directionof vrotationthereof, and means for effecting a counter-currentowbetween streams offluid positioned on opposite sides of said wall.

3, In a heat exchanger for the transfer' of heat between streams offluid mediums, three closely spaced walls, the intermediate wall beingof heatconducting material, two of said walls being rotatable and formedas' surf-aces 'of revolution., said streams adapted to ow on oppositesides of said intermediate wall and being confined by the respectiveother walls, means for simultaneously moving said intermediate wall ando-ne other Of said walls, and a plurality of bai-lies' on the remainingwall open to said intermediate wall and guiding one of said streams,said baiiles extending A at an angle to the axis. of rotation. of themoving walls andbeingfcurved in the ydirection of rotation thereof.V Y Y4. In a heat exchanger for the transfer of heat between a gaseous streamand a liquid stream, three walls in the form of surfaces of revolution,abo-ut Ya vertical axis the intermediate one being of heat-conductingmaterial, means for causing said liquid stream to flow downwardlybetween Said intermediate wall and one other wall, means for causingsaid gaseous stream to flow upwardly between said intermediate wall andthe remaining wall, means for rotating the two walls enclosing saidliquid stream, and impeller means between said two` walls for acting onsaid liquid stream.

5. In a heat exchanger for the transfer of heat between a gaseousVstream and a liquid stream, three Walls inthe form of surfaces ofrevolution, about a vertical axis the intermediate one being ofheat-co-nducting material, means for causing said `liquid stream to flowdownwardly between said 'intermediate wall and one other wall, means forcausing said gaseous' stream to flow upwardly between said intermediatewall and theV remaining wall, means for rotating the two walls enclosingsaid liquid stream, impellermeansV between said two walls for acting onsaid liquid stream, and a plurality of baifles on the'remaining wall forguiding said gaseous stream.

6. In a heat exchanger for the transfer of heat between streams of fluidmediums, three spaced Walls, the intermediate one being ofheat-conducting material, said streams flowing on opposite sides of saidintermediate wall and being co-nfined by the respective other walls,means for simultaneously moving said intermediate wall and one other ofsaid walls, and helical baiile means on the remaining wall open toV saidintermediate wall and being curved at an angle to the direction ofmovement of said intermediate wall for progressively guiding one of saidstreams angularly with respect to the other.

'7. In a heat exchanger for the transfer of heat between streams offluidmediums, three spaced walls, the intermediate one being ofheat-conducting material, said streams fiowing on opposite sides of saidintermediate wall and being confined by the respective other walls,means for simultaneously moving said intermediate wall and one other ofsaid walls, and a plurality of bailles on the remaining wall open tosaid inter-V mediate wall, said Ybaiiles being curved at an angle to thedirection of movement of said in,-

termediate wall, whereby the stream partly con.- ned by said remainingwall is induced to follow the movement of said moving intermediate wallalong said baffles.

8. In a heat exchange-r for the transfer of heat between streams of uidmediums, three spaced walls, the intermediate one being ofheat-conducting material, said streamsowing on opposite sides of saidintermediate wall and being confined by the respective other walls,means for simultaneously moving said intermediate wall and one other ofsaid walls, and helical baffle means on the remaining wall open to saidlintermediate wail, and being curved at an angle to the direction ofmovement of said intermediate wall whereby the movement of saidintermediate wall frictionally drives the stream confined between it andsaid remaining wall along said helical baie means. Y 9. In a heatexchanger for the transfer of hea between streams of fluid mediums,three spaced walls, the intermediate one being of heat-conductingmaterial, said streams iiowing on opposite sides of said intermediatewall and being confined by the respective other walls, means forsimultaneously moving said intermediaterwall and one other of saidwalls, and stationary means comprising curved vanes for receiving andguiding the stream confined between said moving walls to thereby convertthe kinetic energy of said stream into hydrostatic pressure. Y

10. Heat exchange apparatus'comprising two spaced movable walls in theform of similar surfaces of revolution with a common axis and adapted toconfine a fluid stream therebetween,

a third wall positioned to confine a separate iiuid stream in heatexchange relation with said first named stream, a fluid outlet adjacentsaid axis, and stationary means disposed between said movable wallscomprising spaced curved varies for receiving and guiding said firstname-d stream towards said outlet to thereby convert the kinetic energythereof intok hydrostatic pressure, L

ll. In a heat exchanger'for the transfer of heat between streams offluid mediums, traveling in substantially opposite senses, a wall ofheat conducting material constituting a surface of revolution, disposedbetween said streams, means for moving said wall Varound an axis kandtransversely to said streams to increase the velocity of one of thestreams relative to that of said wall, baiile means curved at an angletothe direction of movement of saidwall for coniining and guiding one ofsaid streams, said one stream receiving the mechanical energy to sustainits flow from said moving wall by virtue of its frictional drag thereonand being guided by said bale means, a second wall constituting asurface of revolution movable around said axis for conning and guidingthe other stream and imparting to it a rapid movement along with thefirst named wall, and means located between said walls for subsequentlyretarding said other stream to transform a substantial part of itskinetic energy into hydrostatic pressure thereby to change both thetemperature and the pressure of said other stream.

12. In a heat exchanger for the transfer of heat between streams offluid mediums, traveling in substantially opposite senses, a wall ofheat con-ducting material constituting a surface of gio revolutionVdisposed between said streams, means for moving said Wall around anaxis and transversely to said streams to increase its velocity relativethereto, means including angularly disposed bale means for conning andguiding one of said streams, said one stream receiving mechanical energyto sustain its flow from said moving wall by virtue of its frictionaldrag thereon and being guided by said baille means; impelling means anda second movable wall con- 10 stituting a surface of revolution movablearound said axis and ooacting With said first named wall to impart arapid movement to the other stream, and stationary means located betweensaid Walls for thereafter receiving and retarding said other streamy totransform a substantial part of its kinetic energy into hydrostaticpressure thereby to change both the temperature and the pressure of saidother stream.

FRANK H. CORNELIUS.

WALKER N. GREEN.

